Thread-controlling device for sewing-machines.



c. H. T. HAGELSTEIN.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATION FILED MAY 5 I917.

1%39397 PatentedSept. ll, 1917.

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C. H. T. HAGELSTEIN.

THREAD CONTROLLING DEVICE FOR SEWING MACHINES.

APPLICATIQN FILED MAY 5, 1917- 1 $39,907 Patented Sept. 11, 191?.

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mvrr eras rannr rnron CHRISTIAN H. T. HAGELSTEIN, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO THE REESE BUTTON HOLE MACHINE COMPANY, OF BOSTON, MASSACHUSETTS, A CORPORATION v OF MAINE.

HAenLsTErN, a citizen of the United States,

residing at Boston, county of Suffolk, State of Massachusetts, haveinventedan Improvement in Thread-Controlling Devices for Sewing-Machines, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawingrepresenting like This invention relatesv to buttonhole sewing machines and particularly to means for controlling the tension on the upper thread. One familiar type of buttonhole sewing machine is that which includes stitch-forming mechanism work-holding means, and a rotatable cam for producing a relative movement between the stitch-forming mechanism and work-holding means both during the stitching operation on a buttonhole and also at the end of a stitching operation thereby to carry the work from stitching to button hole-cutting position. Buttonhole sewing machines of this type are also usually provided with a tension for the thread, and it is desirable that during the stitching operation the tension device should be operative to apply considerable tension to the thread, while at the end of the stitching operation it is desirable to relievethe tension on the thread so that the thread may be readily drawn out if necessary. Furthermore in some machines it is desirable to relieve the tension on the upper thread at each end of the buttonhole.

. The object ofmy present invention is to provide an improved device for releasing the tension on the thread which is controlled directly from the feed cam so that the releasing of the tension on the thread and the application of the tension to the thread may be accomplished in accurate timed relation with the movements of the other parts of the machine. 7

In order to give an understanding of my invention, I have illustrated in the drawings a selected embodiment thereof which will now be described, after which the novel features will be pointed out in the appended claims.

Figure 1 is a fragmentary sectional view of a buttonhole sewing machine having my improvements applied thereto, sald sectlon Specification of Letters Patent.

being taken approximately on the line 1--1,

patents, it will not be necessary to further- THREAD-CONTROLLING DEVICE FOR SEWING-MACHINES.

Patented Sept. 11, 191?.

Application filed May 5, 1917. Serial N 0. 166,593.

Fig. 4:;

Fig. 2 is an enlarged sectional through the tension device;

Fig. 3 is a sect-ion on the line 33, Fig. 2;

Fig. 1 is a side view of a portion of a buttonhole sewing machine such as shown 1n Fig. 1.

The buttonhole sewing machine herein illustrated has a frame 1 carrying the usual stitch-forming mechanism which comprises a needle 2 and its needle-bar 3 for manipulating the upper thread and also an under thread-handling mechanism which is not herein illustrated; work-holding means comprising-a clamp-plate 4 and work-clamps 5 that are operative to clamp the work to the clamp-plate, and a rotatable feed cam 6 which is constructed to produce a relative movement between the work-holding means and stitch-forming mechanism both during the stitching on a buttonhole and also after the stitching has been completed and the stitch-forming mechanism has been brought to rest thereby to shift the work from stitching to buttonhole-cutting position in which the buttonhole may be cut by the buttonhole cutter 7. Inasmuch as buttonhole-sewing view , machines having these general features are in common use and are illustrated in various describe the details of construction.

The frame 1 carries a tension device for the upper thread. This tension device is in the form of two friction disks 8 and 9 between which the thread is led andwhich are loosely mounted on a sleeve 10 that in turn is carried by a split stud 141 secured to the bracket 11 supported on the frame 1. The disk 8 is pressed against the disk 9 thereby to apply the desired tension on the thread by means of a spring 12, one end of which rests against a washer 13 loosely mounted on the sleeve 10, the other end of which is backed by a nut 15 that is screwthreaded on the stud 14. The washer 13 is provided with two apertures 16 separated by a bridge-piece 17. The two halves of the split stud 14 extend through the apertures 16 and the bridge-piece 17 extends through the slot 18 formed in the stud. 19 is a ten sion-releasing pin which extends axially of the stud and engages the bridge-piece 17 so that movement of the releasing pin to the 20 is an elbow lever pivoted to the bracket 7 11 at 21, one arm of said lever a flange'22 adapted to engage the releasing pin so that turning movement of the lever in one direction will release the tensionon the thread.

My present invention comprehends a novel device for actuating the lever 20 to relieve the tension 011 the thread at the proper time in the cycle of operations. I

accomplish this herein by the following a link 23, the lower end of which is pivotally connected to an arm 2% that is fast on a rod25 extending through the bed plate26 of theframe' 1 and capable of vertical movement. This rod 25 is acted upon by aspring thereby to relieve thetension. This'spr'ing constitutes automatically -'operative means for relieving the tensionon the thread. S ecuredto the lower'end of the rod'25 is an *arm or finger 28 that is adapted tofhave contactwith the under face of the feed cam 6. This under face of the feedbam is'provided with a high portion 29 and a low' portion 30, said high and low portions being so situated as to engage the finger 28 as the canrr otates. WVhen the high portion 29 of the cam is 111 engagement wlth the finger 28,

as shown in Fig.1, then the rod 25 is drawn downwardly against the action of the spr ing 27 thereby withdrawing the flange 22of the Y lever 20 from operative engagement with the releasing pin 19. This allows the spring 12 to become operative to apply the neces sary tension to the thread. VVhen the caInG turns so that the low portion 30 is inline with the finger 28, then the rod 25is permitted to rise under the in'fluence of the spring 27 thereby turning the elbowlever 20 and actuating-the releasing pin 19 thereby to relieve the tension on the thread. "It will be understood, of course that the spring 27 is stronger than'the spring 12, so that when the low portion .30 of the cam-is in "line with the finger 28 the spring 27 will overcome the spring 12.

i The high and low portions on the cam will be so situated as to causeth'e tension to be released or applied at the desired times in "th'e'cycle ofoperation. Ifit is'de'sirable to have the full tension on' the thread during the stitching along the sides'of the buttonhole'and to release the tension at each end of the buttonhole the high and low portions on the cam will be properly placed to"pro- Vcluce this result. On the other, hand if it' is Pivotally secured to the elbow-lever 20 is the high and low portions 29 and 30 on the cam will be so situated that the high por tion l be i en ag me riflrthafias '2 d 'r neifl remain 9f the i t fish 0H the buttonhole; thus permitting the thread to be subjected to the full tension of the tension device,pwhile just ,aft,er;,the stitching on a buttonhole has been completed and while the cainis partaking of its turning movement by which it brings the work from stitching to butt'onhole ctitting position, the low portion 30 of the cam will come over the finger 28, i thus permitting-theisp 2":

11d turn thef l ever 20 to a relieve the ten'sio Bythe'tiine thattllestit'ching 1 27" which tendsto move it'fupwardlyand a wi be een th tth t s n-see n memes: rs" centreuea directly aler ed cam and thus the proper timing ot thkabp er atibii of the tension 'ldevicerelativ'e 'tojthe said au't'o'i'natically-operativefmeans inoperm completed? v 2.'*I11'a sewmg inachme the combination with a framefcaifryingstitclhforihiiig'inech- "'anism; of'ivork-holdin oain"l:or producing relative movejinentlbe- [tween tliestitcli' forming mechanism and p y -mean'sfa tlifreadyten- 33 9 n a tometwal rop r tive ean tending to releasethe tension; a rotary feed work-holding means, "saidfe'ed "cam being operative during a portion of its rotation to hold sald automatically operatlve"means moperatlve and durlng another portioirfof its rotation to :permitsa'id aut0matically operative means "thread. 1 r

3(In a buttonhole sewing, machine, the combination "with" frame carrying; stitchformin'g inechahism, of work holding means, 7

a rotary, feed cam for producing relative movment between saith. stitch forming mechanism and work-holding means'fsaid feed cam having'a high portion and a low portion} a tension device for applying tentefr iieve tension on' the" sion to the thread'fa lever'for"releasing'the 1 tension, a rod connected to said leverfa spring acting. on {theflrod and tending to actuate, said leven n a dlrec't on 'torelieve the tension, and a finger carried by said rod and adapted to engage the high and low portions of the feed cam as the latter rotates.

4. In a sewing machine, the combination with a frame carrying stitch-forming mechanism, of work-holding means, a tension device for the thread, automatically-operative means tending to release the tension, a feed cam for producing relative movement between the stitch-forming mechanism and work-holding means, and means rigid With said cam for holding said automatically-operative means inoperative until the cam is in a predetermined position.

5. In a sewing machine, the combination with a frame carrying stitch-forming mechanism, of work-holding means, a tension device for the thread, a spring tending to release the tension, a feed cam for producing relative movement between said stitch-forming mechanism and Work-holding means, and means operating in timed relation with said cam for holding the spring inoperative until the cam is in a predetermined position.

In testimony whereof, I have signed my name to this specification.

CHRISTIAN H. 'l'. HAGELSTEIN.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

